Hybrid module with multi-gerotor pump

ABSTRACT

A multi-gerotor pump includes a shaft, rotatable about an axis, a first gerotor pump, a second gerotor pump, a housing, and a reservoir. The first gerotor pump has a first inner gerotor rotationally fixed to the shaft and the second gerotor pump has a second inner gerotor, axially offset from the first inner gerotor, and rotationally fixed to the shaft. The housing has a first gerotor pump inlet channel and a first gerotor pump outlet channel, and a second gerotor pump inlet channel and a second gerotor pump outlet channel. The first gerotor pump outlet channel and the second gerotor pump inlet channel are in fluid communication with the reservoir.

TECHNICAL FIELD

The present disclosure relates generally to a gerotor pump, and more specifically to a hybrid module with a multi-gerotor pump.

BACKGROUND

Gerotor pumps are known. One example is shown and described in commonly-assigned U.S. patent application Ser. No. 17/169,615 titled MOTOR-PUMP SYSTEM to Hrusch et al., hereby incorporated by reference as if set forth fully herein.

SUMMARY

Example embodiments broadly comprise a multi-gerotor pump including a shaft, rotatable about an axis, a first gerotor pump, a second gerotor pump, a housing, and a reservoir. The first gerotor pump has a first inner gerotor rotationally fixed to the shaft and the second gerotor pump has a second inner gerotor, axially offset from the first inner gerotor, and rotationally fixed to the shaft. The housing has a first gerotor pump inlet channel and a first gerotor pump outlet channel, and a second gerotor pump inlet channel and a second gerotor pump outlet channel. The first gerotor pump outlet channel and the second gerotor pump inlet channel are in fluid communication with the reservoir.

In some example embodiments, the multi-gerotor pump also includes an electric pump motor for rotating the shaft. In an example embodiment, the first gerotor pump also has a first outer gerotor, the electric pump motor is arranged to rotate the first outer gerotor, and the first outer gerotor is arranged to rotate the first inner gerotor to rotate the shaft.

In some example embodiments, the first gerotor pump is a scavenger pump for transporting oil from an outlet of a hybrid module to the reservoir, and the second gerotor pump is a cooling circuit pump for transporting the oil from the reservoir to a cooling circuit of the hybrid module. In an example embodiment, the scavenger pump has a larger pumping capacity than the cooling circuit pump. In an example embodiment, the cooling circuit has an oil cooler.

In an example embodiment, the first gerotor pump inlet channel and the first gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir. In an example embodiment, the second gerotor pump inlet channel and the second gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir. In some example embodiments, the shaft extends axially into the reservoir. In an example embodiment, the reservoir has an axial width and the second gerotor pump is disposed within the axial width of the reservoir.

Other example embodiments broadly comprise a hybrid module including a module housing, an e-machine including a stator fixed to the housing and a rotatable rotor, and the multi-gerotor pump arranged to circulate a cooling fluid throughout the module housing. In some example embodiments, the module housing has an outlet and a cooling circuit, the first gerotor pump is a scavenger pump for transporting the cooling fluid from the outlet to the reservoir, and the second gerotor pump is a cooling circuit pump for transporting, the cooling fluid from the reservoir to the cooling circuit. In some example embodiments, the outlet is arranged at a bottom of the module housing when the hybrid module is installed in a vehicle. In an example embodiment, the outlet is arranged such that a cooling fluid level in the housing is less than a bottom of the rotatable rotor.

In an example embodiment, the reservoir is arranged on an axial side of the module housing when the hybrid module is installed in a vehicle. In an example embodiment, the cooling circuit has a spray port in the module housing directed towards a top of the stator when the hybrid module is installed in a vehicle. In an example embodiment, the cooling circuit has a cooling fluid cooler.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of a fluid circuit for a multi-gerotor pump according to an example embodiment.

FIG. 2 illustrates a cross-sectional view of a hybrid module showing a multi-gerotor pump scavenging fluid according to an example embodiment.

FIG. 3 illustrates a cross-sectional view of the hybrid module of FIG. 2 showing a partial cooling circuit.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Also, it is to be understood that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.

The terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the following example methods, devices, and materials are now described.

The following description is made with reference to FIG. 1 . FIG. 1 illustrates a schematic view of fluid circuit 100 for multi-gerotor pump 102 according to an example embodiment. Multi-gerotor pump 102 includes shaft 104, rotatable about axis 106, gerotor pumps 108 and 110, housing 112 and reservoir 114. Gerotor pump 108 includes inner gerotor 116 rotationally fixed to the shaft and gerotor pump 110 includes inner gerotor 118, axially offset from inner gerotor 116 and rotationally fixed to the shaft. The housing includes inlet channels 120 and 122, and outlet channels 124 and 126. As shown in the figure, outlet channel 124 and inlet channel 122 are in fluid communication with the reservoir. Multi-gerotor pump 102 also includes electric pump motor 128 for rotating the shaft.

In the example embodiment shown in FIG. 1 , gerotor pump 108 is a scavenger pump for transporting oil from outlet 130 of hybrid module 132 to the reservoir, and gerotor pump 110 is a cooling circuit pump for transporting the oil from the reservoir to cooling circuit 134 of the hybrid module. Here, the scavenger pump has a larger pumping capacity than the cooling circuit pump so that the reservoir always contains oil available for the cooling circuit pump. As shown in FIG. 1 , cooling circuit 134 includes oil cooler 136. Oil cooler 136 may be a liquid-liquid cooler that uses coolant from another circuit (e.g., engine coolant entering and exiting through ports 138 and 140) to cool the oil.

The following description is made with reference to FIGS. 2-3 . FIG. 2 illustrates a cross-sectional view of hybrid module 232 showing multi-gerotor pump scavenging fluid according to an example embodiment. FIG. 3 illustrates a cross-sectional view of the hybrid module of FIG. 2 showing partial cooling circuit 234. FIG. 2 and FIG. 3 are taken through different, circumferentially-offset portions of hybrid module 232. Multi-gerotor pump 202 includes shaft 204, rotatable about axis 206, gerotor pumps 208 and 210, housing 212 and reservoir 214. Gerotor pump 208 includes inner gerotor 216 rotationally fixed to the shaft and gerotor pump 210 includes inner gerotor 218, axially offset from inner gerotor 216 and rotationally fixed to the shaft. The housing includes inlet channels 220 and 222, and outlet channels 224 and 226. As shown in the figure, outlet channel 224 and inlet channel 222 are in fluid communication with the reservoir.

Multi-gerotor pump 202 also includes electric pump motor 228 for rotating the shaft. Gerotor pump 208 includes outer gerotor 229 and electric pump motor 228 is arranged to rotate the first outer gerotor. Outer gerotor 229 is arranged to rotate the inner gerotor 216 to rotate shaft 204. Operation of gerotor pump 208 is similar to that shown and described in commonly-assigned U.S. patent application Ser. No. 17/169,615 titled MOTOR-PUMP SYSTEM to Hrusch et al., hereby incorporated by reference as if set forth fully herein.

In the example embodiment shown in FIG. 2 , gerotor pump 208 is a scavenger pump for transporting oil from outlet 230 of hybrid module 200 to the reservoir, and, as shown in FIG. 3 , gerotor pump 210 is a cooling circuit pump for transporting the oil from the reservoir to cooling circuit 234 of the hybrid module. Here, the scavenger pump has a larger pumping capacity than the cooling circuit pump so that the reservoir always contains oil available for the cooling circuit pump. Cooling circuit 234 may include a liquid-liquid oil cooler (not shown) that uses coolant from another circuit (e.g., engine coolant) to cool the oil.

As shown in FIG. 2 , gerotor pump inlet channel 220 and gerotor pump outlet channel 224 are both partially disposed axially between gerotor pump 208 and the reservoir. Similarly, as shown in FIG. 3 , gerotor pump inlet channel 222 and gerotor pump outlet channel 226 are partially disposed axially between the gerotor pump 208 and the reservoir. Shaft 204 extends into the reservoir and gerotor pump 210 is disposed within axial width 242 of reservoir 214.

Hybrid module 232 is arranged for connection to an internal combustion engine of a vehicle (not shown) at module housing 244 and input damper 246, for example. Module 232 includes e-machine 248 with stator 250, fixed to the housing, and rotatable rotor 252. The hybrid module also includes multi-gerotor pump 202 arranged to circulate a cooling fluid throughout the module housing. Module housing 244 includes outlet 230 and cooling circuit 234. As described above, gerotor pump 208 is a scavenger pump for transporting the cooling fluid from the outlet to the reservoir, and gerotor pump 210 is a cooling circuit pump for transporting the cooling fluid from the reservoir to the cooling circuit. As shown in FIG. 2 , for example, the outlet is arranged at a bottom of the module housing when the hybrid module is installed in a vehicle such that cooling fluid level 254 in the housing is less than bottom 256 of the rotatable rotor. As shown in FIGS. 2-3 , the reservoir is arranged on an axial side of the module housing when the hybrid module is installed in a vehicle. Cooling circuit 234 includes spray port 258 in the module housing directed towards a top of the stator when the hybrid module is installed in a vehicle. As discussed above, the cooling circuit may include a cooling fluid cooler (not shown in FIGS. 2-3 ).

Hybrid module 132 in FIG. 1 includes elements similar to 2XX elements of module 232 labeled as 1XX. For example, stator 150 in FIG. 1 is comparable to stator 250 in FIGS. 2-3 . Coolant from spray port 158/258 passes through stator 150/250 and rotatable rotor 152/252 before collecting in housing sump 160/260 and exiting through outlet port 130/230. The reservoir maintains a sufficient cooling fluid capacity with a minimal housing sump, thereby enabling a more compact radial packaging of the hybrid module.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.

REFERENCE NUMERALS

-   -   100 Fluid circuit     -   102 Multi-gerotor pump     -   104 Shaft     -   106 Axis     -   108 Gerotor pump (first)     -   110 Gerotor pump (second)     -   112 Housing     -   114 Reservoir     -   116 Inner gerotor (first)     -   118 Inner gerotor (second)     -   120 Inlet channel (first gerotor pump)     -   122 Inlet channel (second gerotor pump)     -   124 Outlet channel (first gerotor pump)     -   126 Outlet channel (second gerotor pump)     -   128 Electric pump motor     -   130 Outlet (hybrid module)     -   132 Hybrid module     -   134 Cooling circuit     -   136 Oil cooler     -   138 Engine coolant inlet port     -   140 Engine coolant outlet port     -   150 Stator     -   152 Rotatable rotor     -   158 Spray port     -   160 Housing sump     -   202 Multi-gerotor pump     -   204 Shaft     -   206 Axis     -   208 Gerotor pump (first)     -   210 Gerotor pump (second)     -   212 Housing     -   214 Reservoir     -   216 Inner gerotor (first)     -   218 Inner gerotor (second)     -   220 Inlet channel (first gerotor pump)     -   222 Inlet channel (second gerotor pump)     -   224 Outlet channel (first gerotor pump)     -   226 Outlet channel (second gerotor pump)     -   228 Electric pump motor     -   229 Outer gerotor (first)     -   230 Outlet (hybrid module)     -   232 Hybrid module     -   234 Cooling circuit     -   238 Engine coolant inlet port     -   240 Engine coolant outlet port     -   242 Axial width (reservoir)     -   244 Module housing.     -   246 Input damper     -   248 E-machine     -   250 Stator     -   252 Rotatable rotor     -   254 Housing cooling fluid level     -   256 Bottom of rotatable rotor     -   258 Housing spray port     -   260 Housing sump 

What is claimed is:
 1. A multi-gerotor pump, comprising: a shaft, rotatable about an axis; a first gerotor pump comprising a first inner gerotor rotationally fixed to the shaft; a second gerotor pump comprising a second inner gerotor, axially offset from the first inner gerotor, rotationally fixed to the shaft; a housing comprising: a first gerotor pump inlet channel and a first gerotor pump outlet channel; a second gerotor pump inlet channel and a second gerotor pump outlet channel; and a reservoir, wherein the first gerotor pump outlet channel and the second gerotor pump inlet channel are in fluid communication with the reservoir.
 2. The multi-gerotor pump of claim 1 further comprising an electric pump motor for rotating the shaft.
 3. The multi-gerotor pump of claim 2, wherein: the first gerotor pump further comprises a first outer gerotor; the electric pump motor is arranged to rotate the first outer gerotor; and the first outer gerotor is arranged to rotate the first inner gerotor to rotate the shaft.
 4. The multi-gerotor pump of claim 1 wherein: the first gerotor pump is a scavenger pump for transporting oil from an outlet of a hybrid module to the reservoir; and the second gerotor pump is a cooling circuit pump for transporting the oil from the reservoir to a cooling circuit of the hybrid module.
 5. The multi-gerotor pump of claim 4 wherein the scavenger pump has a larger pumping capacity than the cooling circuit pump.
 6. The multi-gerotor pump of claim 4 wherein the cooling circuit comprises an oil cooler.
 7. The multi-gerotor pump of claim 1 wherein the first gerotor pump inlet channel and the first gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir.
 8. The multi-gerotor pump of claim 1 wherein the second gerotor pump inlet channel and the second gerotor pump outlet channel are at least partially disposed axially between the first gerotor pump and the reservoir.
 9. The multi-gerotor pump of claim 1 wherein the shaft extends axially into the reservoir.
 10. The multi-gerotor pump of claim 9 wherein: the reservoir comprises an axial width; and the second gerotor pump is disposed within the axial width of the reservoir.
 11. A hybrid module comprising: a module housing; an e-machine comprising a stator fixed to the housing and a rotatable rotor; and the multi-gerotor pump of claim 1 arranged to circulate a cooling fluid throughout the module housing.
 12. The hybrid module of claim 11, wherein: the module housing comprises an outlet and a cooling circuit; the first gerotor pump is a scavenger pump for transporting the cooling fluid from the outlet to the reservoir; and the second gerotor pump is a cooling circuit pump for transporting the cooling fluid from the reservoir to the cooling circuit.
 13. The hybrid module of claim 12, wherein the outlet is arranged at a bottom of the module housing when the hybrid module is installed in a vehicle.
 14. The hybrid module of claim 13, wherein the outlet is arranged such that a cooling fluid level in the housing is less than a bottom of the rotatable rotor.
 15. The hybrid module of claim 12, wherein the reservoir is arranged on an axial side of the module housing when the hybrid module is installed in a vehicle.
 16. The hybrid module of claim 12, wherein the cooling circuit comprises a spray port in the module housing directed towards a top of the stator when the hybrid module is installed in a vehicle.
 17. The hybrid module of claim 12, wherein the cooling circuit comprises a cooling fluid cooler. 